Axel assembly

ABSTRACT

An axle assembly having a wheel flange with a central opening and a slot having an end dimensioned to fit within the wheel flange central opening. A molten binder, such as molten zinc, fills the space in between the wheel central opening and the shaft end. Upon cooling, the binder locks the wheel flange and shaft together.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of application Ser. No.15/298,326 filed on Oct. 20, 2016 which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION I. Field of the Invention

The present invention relates to an axle assembly for small motorsincluding a method for constructing the same.

II. Description of Related Art

There are many products, such as snowmobiles, golf carts, chainsaws,small motorized vehicles, and the like, which utilize small internalcombustion engines to power them. In these products, the overall cost ofconstruction is an important, if not the most important, criteria forthe engine.

Many of these devices that are powered by an internal combustion engineinclude an axle assembly and transmission having a shaft with a wheelflange formed at one end of the shaft. Previously, many of these axleassemblies have been of a one piece construction in which the axleassembly is first formed by casting a metal part in the general form ofthe axle assembly and thereafter machining the molded part to its finalform. Such machining, furthermore, often requires a plurality ofdifferent machining operations.

The necessity to perform multiple machining operations, as well as theinitial forging operation, in order to completely machine the axleassembly is not only time consuming, but expensive. Indeed, the expenseof the axle assembly significantly increases the overall cost of theengine.

SUMMARY OF THE PRESENT INVENTION

The present invention provides an axle assembly which overcomes theabove-mentioned disadvantages of the previously known axle assemblies.

In brief, the axle assembly of the present invention comprises a wheelflange having a central opening. Preferably, the wheel flange is formedfrom powdered metal which requires little or no further machining afterthe wheel flange is molded from the powdered metal. The wheel flange maybe formed from any conventional powdered metal material and includes acentral opening.

An elongated shaft then has an end connection to fit within the wheelflange central opening. The shaft itself is machined from metal, such assteel, in the conventional fashion. Furthermore, one end of the shaftincludes a plurality of external splines.

The splined end of the shaft is dimensioned to fit within the centralopening of the wheel flange. When the wheel flange and shaft are alignedas desired relative to each other, a binder, such as liquid zinc, isthen injected in between the wheel flange and the shaft so that, uponcooling, the binder locks the wheel flange and shaft together.Additional through openings through the wheel flange are preferablyformed which also receive the binder. Consequently, once the binder hascooled and solidified, the wheel flange and shaft are rigidly heldtogether.

BRIEF DESCRIPTION OF THE DRAWING

A better understanding of the present invention will be had uponreference to the following detailed description when read in conjunctionwith the accompanying drawing, wherein like reference characters referto like parts throughout the several views, and in which:

FIG. 1 is an elevational view illustrating a preferred embodiment of thepresent invention;

FIG. 2 is a fragmentary exploded view illustrating the assembly of theaxle assembly;

FIG. 3 is an exploded fragmentary side view;

FIG. 4 is a fragmentary longitudinal sectional view of the axle assemblyprior to injection of the molten zinc;

FIG. 5 is a view similar to FIG. 3 but after the zinc injection; and

FIG. 6 is an end sectional view.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION

With reference first to FIGS. 1 and 2, a preferred embodiment of theaxle assembly 10 of the present invention is shown. The axle assembly 10includes an elongated shaft 12 having a wheel flange 14 attached at oneend 16 of the shaft 12 in a fashion that will be subsequently describedin greater detail.

The wheel flange 14 is preferably constructed from powdered metal whichis molded into its desired shape by a mold (not shown) and thensintered. Consequently, the overall shape of the wheel flange 14 isgenerally flat and planar. Furthermore, little, if any, machining isrequired after the wheel flange 14 is molded into its desired shape andsintered which results in a low-cost construction.

Referring now particularly to FIGS. 1 and 3, the wheel shaft 12 isconstructed in a conventional fashion from a hard material, such as asteel alloy. The shaft is machined into its form and, once the machiningis completed, heat treated for increased strength of the shaft 12. Anyconventional means, such as induction heating, may be used to strengthenthe shaft 12 and a final grinding operation may be performed followingthe heat treatment of the shaft 12.

As best shown in FIGS. 2 and 3, the wheel flange 14 includes a centralthroughbore 20 having a diameter greater than the diameter of the end 16of the shaft 12. This end 16 of the shaft 12 is then positionedcentrally within the through bore 20 as shown in FIG. 4. Furthermore,the end 16 of the shaft 12 is machined into a noncircular shape, such asby knurling 22.

As best shown in FIGS. 2 and 6, the opening 20 in the flange 14 isnoncircular in shape and includes a plurality of cutouts or scallops 24around the opening 20. Furthermore, at least one, and preferably aplurality of through bores 26 are formed through the wheel flange 14when the wheel flange 14 is initially formed. These through bores 26 arepreferably circumferentially equidistantly spaced around the centralopening 20.

After the wheel flange 14 has been fully molded and the shaft 12machined as previously described, the knurled end 16 of the shaft ispositioned centrally within the wheel flange 20 as shown in FIG. 4.Appropriate jigs (not shown) are employed to align the wheel flange 14and shaft together so that the wheel shaft 12 is perpendicular to thewheel flange 14. The aligned shaft 12 and flange 14 are positionedwithin a mold 29 which forms a molding chamber 31 around the end of theshaft 12 and a central portion of the wheel flange 14.

Molten zinc is cast into the chamber 31 around the end 16 of the shaftso that the liquid zinc 30 fills not only the space between the end 16of the shaft 12 and the wheel flange 14, but also extends through andcompletely fills the holes 26 formed through the wheel flange 14. Thisliquid zinc also fills within the uneven nor noncircular outer surfaceof the shaft 12 as well as within the noncircular recesses in the flange14.

As the zinc 30 cools, the zinc 30 sets and becomes rigid. Upon doing so,the zinc 30 fills not only the noncircular opening 20 and cutouts 24 inthe wheel flange 14, but also the noncircular outer surface of the shaft12 formed by the knurling 22. Consequently, once the molten zinc 30 isset, the zinc 30 rigidly secures the shaft 12 and wheel flange 14together and with the wheel flange 14 perpendicularly aligned relativeto the shaft 12.

From the foregoing, it can be seen that the present invention provides asimple and inexpensive axle assembly which can be accurately andrepeatedly manufactured to high precision at relatively low cost. Havingdescribed my invention, however, many modifications thereto will becomeapparent to those skilled in the art to which it pertains withoutdeviation from the spirit of the invention as defined by the scope ofthe appended claims.

I claim:
 1. A method for constructing an axle assembly comprising thesteps of: forming a wheel flange with a central opening, machining anelongated shaft so that one end of the shaft has a smaller crosssectional shape than said central opening of said wheel flange,positioning said one end of said shaft into said wheel flange centralopening, filing a space between said one end of said shaft and saidwheel flange with a molten binder which, upon setting, mechanicallylocks said shaft and said wheel flange together.
 2. The method asdefined in claim 1 wherein said forming step comprises the step offorming said wheel flange from powdered metal.
 3. The method as definedin claim 1 wherein said machining step comprises the step of formingknurls on said one end of said shaft.
 4. The method as defined in claim1 further comprising the step of heat treating said wheel flange.
 5. Themethod as defined in claim 1 further comprising the step of heattreating said elongated shaft.
 6. The method as defined in claim 5further comprising the step of grinding said elongated shaft followingthe step of heat treating.
 7. The method as defined in claim 1 whereinsaid molten binder comprises molten metal having zinc as one component.8. The method as defined in claim 1 wherein said wheel flange has atleast one through hole spaced radially outwardly from said wheel flangecentral opening and wherein said filling step comprises the step offilling said at least one through hole.
 9. The method as defined inclaim 3 wherein said filling step comprises the step of filling saidknurls.
 10. The method as defined in claim 1 wherein said wheel flangehas a plurality of cutouts formed around said central opening andwherein said filling step comprises the step of filling said pluralityof cutouts.
 11. A method for constructing an axle assembly comprisingthe steps of: forming a wheel flange with a central opening, said wheelflange including a plurality of circumferentially spaced cutouts,machining an elongated shaft so that one end of the shaft has a smallercross sectional shape than said central opening of said wheel flange,positioning said one end of said shaft into said wheel flange centralopening, filing a space between said one end of said shaft and saidwheel flange with a molten binder which, upon setting, mechanicallylocks said shaft and said wheel flange together.
 12. The method asdefined in claim 11 wherein said filling step comprises the step offilling said plurality of cutouts.
 13. A method for constructing an axleassembly comprising the steps of: forming a wheel flange with a centralopening, said wheel flange including a plurality of circumferentiallyspaced cutouts, machining an elongated shaft so that one end of theshaft has a smaller cross sectional shape than said central opening ofsaid wheel flange, said elongated shaft including knurls formed on saidone end of the elongated shaft, positioning said one end of said shaftinto said wheel flange central opening, filing a space between said oneend of said shaft and said wheel flange with a molten binder which, uponsetting, mechanically locks said shaft and said wheel flange together.14. The method as defined in claim 13 wherein said filling stepcomprises the step of filling said knurls.
 15. The method as defined inclaim 13 wherein said filling step comprises the step of filling saidplurality of cutouts.